Plato's move here is so clean it can be easy to miss what it costs. True opinion is already beautiful — already fruitful — and the soul already possesses it, however briefly. What it lacks is permanence, and Plato's solution to impermanence is to bind the soul's natural movement to something fixed: the cause, recollection, the eternal form beneath the flickering opinion. The soul, in this account, is healed of its restlessness by being anchored upward.

But notice what is being named as a problem: that opinions "run away out of the human soul." The soul moves. It does not hold. Things come and go through it. Plato reads this as defect — the soul needs the tie, the fastening, the arrest of motion — and in reading it that way, he inaugurates something that will run for two and a half millennia: the conviction that the soul's unruliness is what philosophy must cure. The motion itself, the coming-and-going, the inability to hold knowledge fast — this is the raw material Plato wants to transcend, and what Homer's figures simply lived inside. What gets staked here is not a theory of knowledge. It is a decision about whether soul's mutability is a wound requiring treatment or a grammar requiring literacy.